Matching Items (16,479)
Filtering by
- Creators: Arizona State University
- Creators: Beethoven, Ludwig van, 1770-1827
Description
The U.S. Department of Agriculture’s (USDA) National School Lunch Program and School Breakfast Program provide nutritious meals to school-age children. USDA’s Community Eligibility Provision (CEP) is designed to extend the reach of these programs by allowing schools in low-income areas to provide free school meals to all students at no cost to families. CEP has been shown to increase school meal participation, nutritional intake, academic achievement, and attendance in previous research studies. This study aims to examine the impact of long-term CEP participation on student weight outcomes. Nurse-measured height and weight data for school years 2013-14 to 2019-20 were collected from 141 K-12 public schools in four low-income cities. School-level prevalence of obesity was calculated from students’ heights and weights using the Centers for Disease Control and Prevention protocol. CEP participation for each school year was obtained from the state Department of Education. Schools in the sample began participating in CEP at different times yielding varying numbers of years of CEP exposure over the study period. Multivariable analyses examined the relationship between school CEP exposure and the prevalence of obesity, controlling for school-level covariates. Multivariable analyses showed that for every additional year of CEP participation, the school-level prevalence of obesity was 0.4% lower (p=0.018). The regression-adjusted obesity prevalence for schools that never participated in CEP was 28.0%, while the obesity prevalence for schools with 6 years of CEP participation was 25.4%. The lower prevalence of obesity in CEP-participating schools was primarily driven by elementary schools. These results suggest that the benefits of CEP participation can cumulate over time, significantly reducing school-level obesity prevalence over time.
ContributorsDykstra, Tatum Nicole (Author) / Ohri-Vachaspati, Punam (Thesis advisor) / Acciai, Francesco (Committee member) / McCoy, Maureen (Committee member) / Arizona State University (Publisher)
Created2024
Description
Amidst mounting global crises spanning environmental, social, and economic domains, sustainability education has emerged as a vital pathway toward a thriving future. However, despite its promise, the concept of sustainability often remains superficial, leaving educators ill-equipped to address its complexities. While efforts to integrate sustainability into education are underway, critical pedagogy, a crucial tool for fostering social change, is notably absent from instructional practices. This action research project utilized critical pedagogy to design and implement a critical professional development (CPD) workshop within a larger fellowship program to center justice within sustainability in both content and pedagogical approach. As a result, participants’ definitions and understandings of sustainability increased across all measurements of extent, breadth, and depth. Specifically, participants redefined collaborative relationships and more prominently included notions of justice and equity in their conceptualizations of sustainability and sustainability education. The use of critical pedagogy encouraged teachers to analyze intersectional oppressive systems and fostered a new, critical perspective on sustainability. In their own educational designs, participants demonstrated an intention to model elements of critical pedagogy, such as dialogic action and permeable content. Finally, in alignment with the intended outcomes of CPD, participants developed cooperative space for co-learning, built unity, shared leadership, and felt confident implementing their own professional development to address context-specific concerns. By using critical pedagogy in sustainability education, the workshop participants prioritized deep and caring relationships which fostered empathic engagement with the intersectional and often dehumanizing systems that have led to interconnected global crises. The results indicated that using CPD as a framework could be effective in teacher professional development for sustainability as a design and implementation tool to center critical work that examines systemic issues of injustice and exploitation against both humans and our planet.
ContributorsCashion, Molly Elise (Author) / Judson, Eugene (Thesis advisor) / Casanova, Carlos (Committee member) / Goebel, Janna (Committee member) / Boyce, Ayesha (Committee member) / Arizona State University (Publisher)
Created2024
Description
Integrating advanced materials with innovative manufacturing techniques has propelled the field of additive manufacturing into new frontiers. This study explores the rapid 3D printing of reduced graphene oxide/polymer composites using Micro-Continuous Liquid Interface Production (μCLIP), a cutting-edge technology known for its speed and precision. A printable ink is formulated with reduced graphene oxide for μCLIP-based 3D printing. The research focuses on optimizing μCLIP parameters to fabricate reduced graphene composites efficiently. The study encompasses material synthesis, ink formulation and explores the resulting material's structural and electrical properties. The marriage of graphene's unique attributes with the rapid prototyping capabilities of μCLIP opens new avenues for scalable and rapid production in applications such as energy storage, sensors, and lightweight structural components. This work contributes to the evolving landscape of advanced materials and additive manufacturing, offering insights into the synthesis, characterization, and potential applications of 3D printed reduced graphene oxide/polymercomposites.
ContributorsRavishankar, Chayaank Bangalore (Author) / Chen, Xiangfan (Thesis advisor) / Bhate, Dhruv (Committee member) / Azeredo, Bruno (Committee member) / Arizona State University (Publisher)
Created2024
Description
Automation is becoming more autonomous, and the application of automation as a collaborator continues to be explored. A major restriction to automation’s application as a collaborator is that people often hold inaccurate expectations of their automated collaborator. Goal alignment has been shown to be beneficial in collaborations and delegation decisions among human-human and human-automation collaborations. Few studies have investigated the difference that goal alignment has on human collaborators compared to automated collaborators. In this 2 (goal aligned or misaligned) x 2 (human or automated) between-subjects study, participants complete a simplified triage patient task and then are given the opportunity to stay with their manual task solution or to delegate their decision and go with their collaborator’s recommendation. Participants never delegated to collaborators with goals that were not aligned to theirs. Participants working with human collaborators that have similar goals to them were more often delegated to and more often associated with a better triage performance. These results can inform the design of similar systems that foster collaboration and achieve better team performance. Although goal alignment was crucial for delegation decisions, it was difficult to achieve complete agreement of goals. Future research should investigate effective methods to better communicate goals among collaborators.
ContributorsLee, Jessica Rose (Author) / Chiou, Erin K (Thesis advisor) / Cooke, Nancy J (Committee member) / Lum, Heather C (Committee member) / Arizona State University (Publisher)
Created2024
Description
The unified model of active galactic nuclei (AGNs) has provided a successful explanation for the observed diversity of AGNs in the local universe. However, recent analysis of multi-wavelength spectral and image data suggests that the unified model is only a partial theory of AGNs, and may need to be augmented to remain consistent with all observations. Recent studies using high spatial resolution ground-and space-based observations of local AGNs show that Seyfert class and the "core" (r less than or similar to 1 kpc) host-galaxy morphology are correlated. Currently, this relationship has only been established qualitatively, by visual inspection of the core morphologies of low-redshift (z < 0.035) Seyfert host galaxies. We re-establish this empirical relationship in Hubble Space Telescope optical imaging by visual inspection of a catalog of 85 local (D < 63 Mpc) Seyfert galaxies. We also attempt to re-establish the core morphology-Seyfert class relationship using an automated, non-parametric technique that combines both existing classification parameter methods (the adapted CAS and G-M-20) and a new method which implements the Source Extractor software for feature detection in unsharp-mask images. This new method is designed explicitly to detect dust features in the images. We use our automated approach to classify the morphology of the AGN cores and determine that Sy2 galaxies visually appear, on average, to have more dust features than Sy1. With the exception of this "dustiness" however, we do not measure a strong correlation between the dust morphology and the Seyfert class of the host galaxy using quantitative techniques. We discuss the implications of these results in the context of the unified model.
ContributorsRutkowski, Michael (Author) / Hegel, P. R. (Author) / Kim, Hwihyun (Author) / Windhorst, Rogier (Author) / Tamura, Kazuyuki (Author) / College of Liberal Arts and Sciences (Contributor) / School of Earth and Space Exploration (Contributor)
Created2013-10-28
Description
The ability to accurately predict the oxidation and reduction potentials of molecules is very useful in various fields and applications. Quantum mechanical calculations can be used to access this information, yet sometimes the usefulness of these calculations can be limited because of the computational requirements for large systems. Methodologies that yield strong linear correlations between calculations and experimental data have been reported, however the balance between accuracy and computational cost is always a major issue. In this work, linear correlations (with an R-2 value of up to 0.9990) between DFT-calculated HOMO/LUMO energies and 70 redox potentials from a series of 51 polycyclic aromatic hydrocarbons (obtained from the literature) are presented. The results are compared to previously reported linear correlations that were obtained with a more expensive computational methodology based on a Born-Haber thermodynamic cycle. It is shown in this article that similar or better correlations can be obtained with a simple and cheaper calculation.
ContributorsMendez-Hernandez, Dalvin (Author) / Pilarisetty, Tarakeshwar (Author) / Gust, Devens (Author) / Moore, Thomas (Author) / Moore, Ana (Author) / Mujica, Vladimiro (Author) / Department of Chemistry and Biochemistry (Contributor) / College of Liberal Arts and Sciences (Contributor) / School of Molecular Sciences (Contributor)
Created2013-10-28
Description
Quantum weak measurements with states both pre- and post-selected offer a window into a hitherto neglected sector of quantum mechanics. A class of such systems involves time dependent evolution with transitions possible. In this paper we explore two very simple systems in this class. The first is a toy model representing the decay of an excited atom. The second is the tunneling of a particle through a barrier. The post-selection criteria are chosen as follows: at the final time, the atom remains in its initial excited state for the first example and the particle remains behind the barrier for the second. We then ask what weak values are predicted in the physical environment of the atom (to which no net energy has been transferred) and in the region beyond the barrier (to which the particle has not tunneled). Thus, just as the dog that didn't bark in Arthur Conan Doyle's story Silver Blaze gave Sherlock Holmes meaningful information about the dog's non-canine environment, here we probe whether the particle that has not decayed or has not tunneled can provide measurable information about physical changes in the environment. Previous work suggests that very large weak values might arise in these regions for long durations between pre- and post-selection times. Our calculations reveal some distinct differences between the two model systems.
ContributorsWalker, Sara (Author) / Davies, Paul (Author) / Samantray, Prasant (Author) / Aharonov, Yakir (Author) / College of Liberal Arts and Sciences (Contributor) / BEYOND: Center for Fundamental Concepts in Science (Contributor) / School of Earth and Space Exploration (Contributor)
Created2014-06-13
Description
There is a substantial literature of correlational findings from studies in developed countries where abortion is legal that are riddled with methodological problems and selective biases that exaggerate post-pregnancy mental health risks of abortion while minimizing risks for unwanted childbearing. Health professionals need to be able to critically evaluate this literature and use caution when generalizing findings across contexts differing in legal grounds for abortion. The impact of diversity in women’s characteristics, circumstances, and reasons for avoiding childbirth has not been adequately incorporated in theory or research seeking to explain the variations that are found in women’s post-abortion mental health. Critical reviews have established that predictors of problems after abortion or childbirth are similar. Further, when a woman has an unwanted pregnancy, i.e., a pregnancy that she does not wish to end in a term birth, the likelihood that she will have post-pregnancy mental health problems is similar regardless of pregnancy outcome (abortion vs. delivery). Selective sampling bias that advantages the delivery group, common risk factors, and confounding of abortion with unintended pregnancy explain the correlation of legal abortion with negative outcomes observed in the literature from developed countries. Meanwhile, documented negative effects of unwanted pregnancy and childbearing are multiple, severe, and long-lasting for mother and child. Changing societal conditions, particularly in developing countries, provide an opportunity for correcting biases and limitations of current research. High quality studies aimed at understanding the varied relationships of unintended pregnancy to mental health outcomes –both positive and negative– in the context of the diverse circumstances of women’s lives are sorely needed. Such studies can inform the development of programs to re- duce unwanted childbearing and promote pre- and post-pregnancy mental health for all women, regardless of how they choose to end their pregnancy.
ContributorsRusso, Nancy (Author) / College of Liberal Arts and Sciences (Contributor) / Department of Psychology (Contributor)
Created2014-07-01
Description
A large fraction of the world grasslands and savannas are undergoing a rapid shift from herbaceous to woody-plant dominance. This land-cover change is expected to lead to a loss in livestock production (LP), but the impacts of woody-plant encroachment on this crucial ecosystem service have not been assessed. We evaluate how tree cover (TC) has affected LP at large spatial scales in rangelands of contrasting social–economic characteristics in the United States and Argentina. Our models indicate that in areas of high productivity, a 1% increase in TC results in a reduction in LP ranging from 0.6 to 1.6 reproductive cows (Rc) per km[superscript 2]. Mean LP in the United States is 27 Rc per km[superscript 2], so a 1% increase in TC results in a 2.5% decrease in mean LP. This effect is large considering that woody-plant cover has been described as increasing at 0.5% to 2% per y. On the contrary, in areas of low productivity, increased TC had a positive effect on LP. Our results also show that ecological factors account for a larger fraction of LP variability in Argentinean than in US rangelands. Differences in the relative importance of ecological versus nonecological drivers of LP in Argentina and the United States suggest that the valuation of ecosystem services between these two rangelands might be different. Current management strategies in Argentina are likely designed to maximize LP for various reasons we are unable to explore in this effort, whereas land managers in the United States may be optimizing multiple ecosystem services, including conservation or recreation, alongside LP.
ContributorsAnadon, Jose Daniel (Author) / Sala, Osvaldo (Author) / Turner II, B. L. (Author) / Bennett, Elena M. (Author) / College of Liberal Arts and Sciences (Contributor) / School of Life Sciences (Contributor) / Julie Ann Wrigley Global Institute of Sustainability (Contributor) / School of Sustainability (Contributor) / School of Geographical Sciences and Urban Planning (Contributor)
Created2014-09-02
Description
The effects of surface pretreatment, dielectric growth, and post deposition annealing on interface electronic structure and polarization charge compensation of Ga- and N-face bulk GaN were investigated. The cleaning process consisted of an ex-situ wet chemical NH[subscript 4]OH treatment and an in-situ elevated temperature NH[subscript 3] plasma process to remove carbon contamination, reduce oxygen coverage, and potentially passivate N-vacancy related defects. After the cleaning process, carbon contamination decreased below the x-ray photoemission spectroscopy detection limit, and the oxygen coverage stabilized at ∼1 monolayer on both Ga- and N-face GaN. In addition, Ga- and N-face GaN had an upward band bending of 0.8 ± 0.1 eV and 0.6 ± 0.1 eV, respectively, which suggested the net charge of the surface states and polarization bound charge was similar on Ga- and N-face GaN. Furthermore, three dielectrics (HfO[subscript 2], Al[subscript 2]O[subscript 3], and SiO[subscript 2]) were prepared by plasma-enhanced atomic layer deposition on Ga- or N-face GaN and annealed in N[subscript 2] ambient to investigate the effect of the polarization charge on the interface electronic structure and band offsets. The respective valence band offsets of HfO[subscript 2], Al[subscript 2]O[subscript 3], and SiO[subscript 2] with respect to Ga- and N-face GaN were 1.4 ± 0.1, 2.0 ± 0.1, and 3.2 ± 0.1 eV, regardless of dielectric thickness. The corresponding conduction band offsets were 1.0 ± 0.1, 1.3 ± 0.1, and 2.3 ± 0.1 eV, respectively. Experimental band offset results were consistent with theoretical calculations based on the charge neutrality level model. The trend of band offsets for dielectric/GaN interfaces was related to the band gap and/or the electronic part of the dielectric constant. The effect of polarization charge on band offset was apparently screened by the dielectric-GaN interface states.
ContributorsYang, Jialing (Author) / Eller, Brianna S. (Author) / Nemanich, Robert (Author) / College of Liberal Arts and Sciences (Contributor) / Department of Physics (Contributor)
Created2014-09-28